Novel types of silicon waveguides fabricated using proton beam irradiation

Abstract

In this work, we describe the use of a combination of proton beam irradiation and electrochemical etching to fabricate high index-contrast waveguides directly in silicon without the need for silicon-on-insulator substrate. Various types of waveguides with air or porous silicon cladding have been demonstrated. We show that porous silicon (PS) is a flexible cladding material due to the tunability of its refractive index and thickness. The Si/PS waveguide system also possesses better transmittance in the ranges of 1.2-9 and 23-200 μm, compared to Si/SiO2 waveguides. This is potentially important for mid and far-IR applications. Since it is compatible with conventional CMOS technology, this process can be used for fabrication of integrated optoelectronics circuits. © 2010 Copyright SPIE - The International Society for Optical Engineering.